This invention is generally in the field of emission control devices. More particularly, the present invention is directed to a device and method of activating sorbent using sorbent activation plates placed in the flue gas flow path.
Sorbents are widely used in power generation systems such as coal-burning power plants to neutralize or capture various combustion by-products. Examples of such sorbents include activated carbon, silica, calcium hydroxide, and sodium bicarbonate. The selection of a sorbent for a particular application is dictated by the type of by-product which is to be captured or eliminated. For example, activated carbon is often used to capture mercury. Calcium hydroxide and sodium bicarbonate are often used to neutralize sulfur dioxide and/or NOx emissions.
Conventionally, sorbents are injected into the combustor or into the flue gas flow path downstream of the combustor. The sorbent is then allowed to mix and/or react with the combustion by-products before the combustion by-products are exhausted to the atmosphere. The sorbent is typically reclaimed from the exhaust flow by filtration or other separation process.
Sorbent utilization increases operating costs both because of the cost of providing the sorbent and the costs of separating and/or disposing the sorbent from the flue gas flow path. As such, it would be desirable to provide a device and method to improve the efficiency of sorbent utilization.